After a Coastal Storm: How to Check Your Chimney Safely

Look from the ground, not the roof

Don’t climb onto a wet or damaged roof to look at a chimney after a storm. Most of what matters can be seen from the yard, the street or an upstairs window, especially with binoculars.

• Is the cap still there, and is it straight?
• Are any bricks missing, loose or out of line at the top?
• Does the chimney lean, or has a gap opened where it meets the house?
• Is the flashing at the base lifted or torn?
• Are there pieces of brick, mortar or metal on the roof or the ground below?

Check inside too

• New water stains on ceilings or walls near the chimney.
• Water, rust or debris in the firebox or on the damper.
• Damp or stained framing next to the chimney in the attic.
• Pieces of tile or mortar in the cleanout of a heating flue.

Wind-driven rain in a storm often finds weak points that ordinary rain never reaches, so a leak that appears only after a storm usually points to the side of the chimney that faced the wind.

When to stop using the chimney

If you see loose or missing brick at the top, a leaning stack, a crushed or missing cap with debris possibly in the flue, or damage from a falling limb, don’t use the fireplace or stove until the chimney has been inspected. NFPA 211 calls for a Level 2 inspection after an external event likely to have caused damage, including a camera look inside the flue.

Heating flues and power outages

A chimney that vents a boiler, furnace or water heater matters even if you never use the fireplace. If storm debris or a damaged cap may have blocked the flue, have it checked before relying on the heat, and make sure carbon monoxide alarms work.

Storms often bring power outages and portable generators. The U.S. Consumer Product Safety Commission warns that a single portable generator can produce as much carbon monoxide as hundreds of cars, and advises keeping generators outdoors, well away from the house. Never run one in a garage, basement or near a window or vent.

Trees, limbs and the chimney

Many storm-damaged chimneys are hit by something rather than simply blown on. A falling limb can crack a crown, knock off a cap or dislodge the top courses. Even without a direct hit, branches whipping against a chimney in high wind wear at mortar and flashing. After a storm, look for broken branches above or beside the chimney and for scraped or broken brick.

Trimming limbs that overhang the roof near the chimney reduces both storm damage and the leaves and animals that find their way into flues. Tree work near a roof and power lines is a job for a qualified arborist.

Flooding and the base of the chimney

Storm surge and heavy rain can flood basements, and in many houses the base of the chimney, with its cleanout door and heating flue connections, sits in the basement. If water reached the base of the chimney, have the cleanout and connector checked, and have your heating technician look at any appliance that was flooded before it is restarted. Wet debris at the base of a flue can block it, and flooded appliances need professional checking before use.

Common findings after storms

• Caps blown off or bent, leaving flues open to rain and animals.
• Top courses loosened or knocked off, especially on tall chimneys.
• Crowns cracked by wind loads or falling limbs.
• Flashing lifted on the windward side, letting driven rain under.
• Water damage inside the flue, damper or smoke chamber from rain pouring down an opened flue.

Most of these are straightforward repairs if dealt with soon. Left through a winter of freeze–thaw, a loosened top or cracked crown usually turns into a bigger job.

Insurance and records

Photograph any damage from the ground as soon as it is safe, with the date. Whether storm damage is covered depends on your policy, and only your insurer can say. A chimney inspection after the storm documents the condition of the chimney with photographs, which you can share with your insurer or adjuster.

Getting ready for the next one

1. Fix cracked crowns, open joints and loose top courses before storm season.
2. Replace rusting or loose caps with properly fastened, corrosion-resistant ones.
3. Have flashing properly stepped and counter-flashed rather than caulked.
4. Trim branches that overhang the chimney.
5. Keep CO alarms working on every level of the home.

Sources we checked

• BSCES: Historic New England Infrastructure — New Bedford Hurricane Barrier
• NFPA 211: Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances
• Chimney Safety Institute of America: The Three Levels of Chimney Inspections
• U.S. Consumer Product Safety Commission: Carbon Monoxide Information Center

General information for homeowners from Chimney Champ’s New Bedford. It cannot stand in for an inspection of your own chimney, and questions about code are decided by your local building or fire official.